Loudspeakers or sound amplifying devices have been heretofor known in which the loudspeaker is divided into a number of segments for dispersing the sounds emanating from the loudspeaker to various portions of a room or auditorium. It is also known to provide valve means for determining which segments of the speaker are to convey the sound from the source thereof which is usually directed to a throat of the speaker which is in turn connected with the various horn segments. Furthermore, the prior art contains devices for adjusting the aforementioned valve.
A rotatable valve V is shown in Thomas U.S. Pat. No. 1,506,393 and is operated by a lever extending to the side thereof to control the acoustical connection to the inner horn and the outer horn 1. Rotatable valve elements also are shown in the horn of Cobb U.S. Pat. No. 986908 and in Swiss Pat. No. 206750 (1939). However, none of the prior art patents disclose an adjustment for a speaker comprising a central horn and two adjacent horns and wherein an adjustment extends forwardly from the horns exteriorly thereof to a position to adjust a valve to provide for the souond passing only through the center horn or alternatively through the center horn and the two outer horns.